Graver Water Systems

 

Graver Water has a fully staffed service department of experienced service engineers available upon request to start-up or troubleshoot your water treatment system. Whether it's chemical, mechanical, electrical, or PLC related, our service department is available to assist you. Graver's support services include: •  Start-up 
•  Commissioning 
•  Erection supervision 
•  Training 
•  Equipment evaluation and upgrade / replacement recommendations Graver Water continues its active role in the retrofit market for existing North American nuclear facilities. Graver Water Systems' Retrofit / Upgrade Program can significantly extend the life of your water treatment equipment. Timely replacements, upgrades and maintenance allow you to reduce costs and operate your water treatment facilities at maximum efficiency. Let Graver show you how we can improve the reliability and availability of your water treatment system by contacting us today.

 

The purification of condensate return by ion-exchange and filtration is an essential part of the power generation process. Impurities may be introduced from sources such as make-up water, condenser cooling water leaks and corrosion of metal surfaces.
Condensate polishing is essential in order to remove these impurities and ensure high quality feedwater to the boilers that meet nuclear water quality specifications. The benefits of condensate polishing include improved availability, minimize corrosion, turbine efficiency, quicker start ups, reduced waste water requirements and reduced need for chemical cleaning.

Corrosion product transport, predominantly iron oxides, is a major issue in thermal power generation. These are especially problematic during startup, when corrosion products are present in larger quantities. Corrosion products hamper plant operations in various ways, such as slowing the rate of startup, fouling ion exchange beds, forming sludges and deposits in steam generators, forming deposits on BWR fuel cladding surfaces and other quiescent locations in the cycle.
Graver Water provides various types of condensate filtration systems from the most sophisticated hollow fiber membrane (HFF) system, to the most economical TurboGuard disposable filter system.
HFF HOLLOW FIBER FILTER - Although the highest equipment cost system, HFF provides extremely long membrane life. Plants in operation in Japan have realized membrane life in excess of 10 years. These systems are particularly attractive for BWR plants since the spent membranes would be a radioactive waste.
HFF membranes require less frequent cleaning. The typical interval is 60 days, so there is less wastewater generation. Each module has an independent scrubbing air distributor to ensure thorough removal of accumulated material during a cleaning cycle. Double inlet and outlet nozzles reduce system DP during operation.
The modules are of single piece construction and the lightweight total plastic construction allows them to be incinerated, crushed or shredded for disposal.
AFA BACK - WASHABLE PLEATED MEMBRANE FILTER - Aegis® AFA Pleated Membrane filtration systems provide a high capacity back-washable system at a moderate capital cost with a septa life of 5-7 years. In the AFA pleated septa, surface area is optimized for both forward filtration flow, as well as backwash flow, and typical backwash frequency is 45 days.
Graver's AEGIS AFA filter elements meet today's demands of multiple backwashing without the loss of the ability to retain iron oxide particles. These filter elements are available in a wide variety of absolute ratings from below 1.0 micron to 20 micron, and can be customized for specific applications. These elements can also be retrofitted into a number of competitive filter designs.
Our filter elements exhibit excellent mechanical strength for backwashing through their 100% plastic construction, while also allowing for easy disposal by crushing, incineration or shredding.
AEGIS AFA filter septa are specifically designed for condensate use. More than 100,000 have been installed in world-wide condensate systems

 

Graver's TurboGuard High Flow Filter is designed specifically for use in condensate streams or other critical utility applications where substantial dirt holding and crud removal properties are essential. TurboGuard High Flow Filters are typically installed upstream of the condensate demineralizers to prevent ion exchange resin bead fouling. Unique Media design is focused specifically on utility applications and the specific contaminants in condensate-type systems.

At periodic intervals, nuclear plants schedule refueling outages to replace a portion of the nuclear fuel. The spent or used fuel still generates heat and radiation and must be handled and stored safely. The fuel assemblies that have been removed from the reactor are stored under water in the Spent Fuel Pool. Good water quality is important to prevent degradation and to help maintain the integrity of the spent fuel assemblies.
An important function of fuel pool cleanup is to control dose rates on the refuel floor and work areas/platforms during refueling outages. This is accomplished by removal of radioactive isotopes, particularly co-60 for BWRs and Co-58 for PWRs. Fuel Pool Cleanup also has an important role in supporting ISFSI (Independent Spent Fuel Storage Installations). Surface activity on the transfer cask (particularly Cs-137) must be maintained low to limit the extent of decontamination required.
Spent Fuel Pool ion exchange systems can be either Powdex® precoat systems or deep beds. Graver Water provides Powdex® systems to simultaneously deionize the water and remove particulates to maintain pool clarity. Deep bed systems offer a higher ion exchange capacity, but not the same level of turbidity reduction. Graver Water has system designs for both precoat (Powdex) filters and deep bed ion exchange polishers for this application.
New design enhancements of Graver's precoat filters, as proven by Organo Corporation in Japan, allow the new fuel pool cleanup systems to treat twice the flow of the original designs.
Ecodex®, the preferred precoat media for fuel pool cleanup, is provided by Graver Water's sister company, Graver Technologies.
For deep beds, a specialty Gravex mix provided by Graver Technologies, containing a high capacity stable cation resin is recommended, since the spent Fuel Pool environment can affect resin properties.

The Reactor Water Cleanup (RWCU) system in a BWR plant is used to remove contaminants from the reactor water. Precoat filter systems (POWDEX) are the process of choice for this application. The reactor water is cooled, treated by the RWCU system, and returned to the reactor, normally via the feedwater piping. The POWDEX precoat provides simultaneous filtration and deionization of reactor water.
The new design enhancements of Graver's precoat filters, allows the new RWCU cleanup systems to treat twice the flow of the original designs, as proven by Organo Corporation in Japan.

 

Steam generators in Nuclear Pressurized Water Reactor (PWR) electric generating stations are vital components in the power generation cycle. In addition to high purity condensate, blow down demineralizers are often used to help maintain quality for efficient operation and extended steam generator life.
These are typically deep bed demineralizers, which must perform in the thermally challenging environment. High quality, specialty products are available through Graver Water's sister company, Graver Technologies to obtain optimum generator and cycle performance in Graver Water's deep Bed demineralizers.